Create a high-resolution 3D model of an underwater oil plume caused by an oil spill. The plume should consist of multiple elongated tendrils of viscous, dark brown oil dispersing into clear water. Emphasize realistic fluid dynamics with smooth, semi-transparent surfaces, glossy reflections, subtle turbidity and suspended particles. Include volumetric density gradients (thicker at the source, gradually fading outward) and light scattering effects from a soft, top-down underwater illumination. Output as a high-polygon mesh with PBR materials (albedo, roughness, normal, transmission) and volumetric data, ready for real-time rendering or further simulation.